Surface Wind/Stress Structure under Hurricanes
Wenqing Tang and W. Timothy Liu
Over eight years of QuikSCAT scatterometer data are used to study the wind-stress relation and the asymmetric pattern of the ocean surface wind/stress fields under hurricanes. QuikSCAT measurements collocated with hurricanes are selected by matching with available operational best track information globally. The azimuthal distribution relative to storm motion of the equivalent neutral wind vectors, backscatter, and precipitation within 500 km distance from hurricane centers are examined and compared with available operational wind products (e.g. HWind from NOAAâ€™s Hurricane Research Division in North Atlantic Ocean). Global data are also separated according to ocean basins and hurricane intensity. The changes of wind-stress asymmetry with translation speed and ocean basin are examined. Despite rain contamination and the saturation of backscatter under high wind, we could still demonstrate the impact of scatterometer observations in understanding organization of convections, air-sea momentum-energy exchange, and evolution and intensification of a hurricane.